Power Transformers and Reactors
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Advanced Transmission Technologies
Advanced Transmission Technologies December 2020 United States Department of Energy Washington, DC 20585 Executive Summary The high-voltage transmission electric grid is a complex, interconnected, and interdependent system that is responsible for providing safe, reliable, and cost-effective electricity to customers. In the United States, the transmission system is comprised of three distinct power grids, or “interconnections”: the Eastern Interconnection, the Western Interconnection, and a smaller grid containing most of Texas. The three systems have weak ties between them to act as power transfers, but they largely rely on independent systems to remain stable and reliable. Along with aged assets, primarily from the 1960s and 1970s, the electric power system is evolving, from consisting of predominantly reliable, dependable, and variable-output generation sources (e.g., coal, natural gas, and hydroelectric) to increasing percentages of climate- and weather- dependent intermittent power generation sources (e.g., wind and solar). All of these generation sources rely heavily on high-voltage transmission lines, substations, and the distribution grid to bring electric power to the customers. The original vertically-integrated system design was simple, following the path of generation to transmission to distribution to customer. The centralized control paradigm in which generation is dispatched to serve variable customer demands is being challenged with greater deployment of distributed energy resources (at both the transmission and distribution level), which may not follow the traditional path mentioned above. This means an electricity customer today could be a generation source tomorrow if wind or solar assets were on their privately-owned property. The fact that customers can now be power sources means that they do not have to wholly rely on their utility to serve their needs and they could sell power back to the utility. -
Power Grid Failure
Power grid failure Presentation by: Sourabh Kothari Department of Electrical Engineering, CDSE Introduction • A power grid is an interconnected network of transmission lines for supplying electricity from power suppliers to consumers. Any disruptions in the network causes power outages. India has five regional grids that carry electricity from power plants to respective states in the country. • Electric power is normally generated at 11-25kV and then stepped-up to 400kV, 220kV or 132kV for high voltage lines through long distances and deliver the power into a common power pool called the grid. • The grid is connected to load centers (cities) through a sub- transmission network of normally 33kV lines which terminate into a 33kV (or 66kV) substation, where the voltage is stepped-down to 11kV for power distribution through a distribution network at 11kV and lower. • The 3 distinct operation of a power grid are:- 1. Power generation 2. Power transmission 3. Power distribution. Structure of Grids Operations of Power grids • Electricity generation - Generating plants are located near a source of water, and away from heavily populated areas , are large and electric power generated is stepped up to a higher voltage-at which it connects to the transmission network. • Electric power transmission - The transmission network will move the power long distances–often across state lines, and sometimes across international boundaries, until it reaches its wholesale customer. • Electricity distribution - Upon arrival at the substation, the power will be stepped down in voltage—to a distribution level voltage. As it exits the substation, it enters the distribution wiring. Finally, upon arrival at the service location, the power is stepped down again from the distribution voltage to the required service voltage. -
Quadrature Booster on UK Power Networks’ 33Kv Distribution Network
The Design and Deployment of a Quadrature Booster on UK Power Networks’ 33kV Distribution Network Gilbert MANHANGWE; Paul DYER; Sotiris GEORGIOPOULOS; and Azzam AL-RIYAMI UK Power Networks, UK [email protected] Abstract Although Quadrature Boosters are a mature technology on electricity transmission networks having developed in the 1960s, available information and references show that, prior to UK Power Networks’ innovative Quadrature Booster trial that commenced in January 2012 none had been deployed on the distribution network. This paper presents the UK Power Networks experience in the design and deployment of a Quadrature Booster at 33kV distribution network through the ‘Flexible Plug and Play’ project. The paper particularly focuses on the Quadrature Booster design characteristics, the network single line diagram and the layout adopted, and the control and operational strategy considerations to effectively manage an identified network constraint using this device. The challenges in modelling studies and testing on such a device are also presented. The paper also discusses (1) the identified network constraint, (2) available options to address the problem, (3) how the network constraint is being addressed or managed, (4) the design, installation, testing and commissioning of this innovative asset to explain the process which UK Power Networks, the involved project partners and contractors undertook, and (5) the benefits and learning accrued from delivering the Quadrature Booster solution. Introduction It is widely recognised that ‘smarter’ ways of managing distribution network assets include improved utilisation of existing assets. The intended effect is to defer the immediate need for traditional reinforcement where possible. UK Power Networks was awarded funding in 2011 under Ofgem’s (GB Energy Regulator) Low Carbon Network Fund mechanism, for the ‘Flexible Plug and Play’ project. -
Performance Study on Commercial Magnetic Sensors Unmanned Aerial
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT, VOL. 69, NO. 4, APRIL 2020 1397 Performance Study on Commercial Magnetic Sensors for Measuring Current of Unmanned Aerial Vehicles Ke Zhu , Xuyang Liu , Student Member, IEEE, and Philip W. T. Pong , Senior Member, IEEE Abstract— The industrial investment in unmanned aerial vehi- UAVs have found many applications, such as condition moni- cles (UAVs) is soaring due to their multiple autonomous applica- toring, geographical mapping, and performing certain danger- tions, such as aerial photography, rescue operations, surveillance, ous tasks, wherein the sensor technologies are indispensable and scientific data collection. Current sensing is critical for determining battery capacity in charging and discharging process for achieving these functions [3]–[7]. These sensors include and alerting for system fault during the flight. Shunt resistors accelerometers, tilt sensors, engine intake flow sensors, mag- and Hall-effect sensors are traditionally used in UAVs. Recently, netic sensors (electronic compasses), and current sensors [8]. magnetoresistive (MR) sensors are gaining enormous attention Among these sensors, current sensors play an important role from researchers. MR sensors tend to consume less power, and for a healthy operation of UAVs such as to prevent overcharg- they are smaller in size than the Hall-effect sensors. In this paper, a number of off-the-shelf MR sensors were investigated ing and safeguard against overcurrent [9], [10]. to evaluate the possibility of applying them for UAVs. Another Four physical principles are typically applied for current type of magnetic sensor (fluxgate) and shunt resistor was also sensors, namely Ohm’s law (shunt resistors), Faraday’s law studied and compared as a reference. -
Power Transmission Engineering JUNE 2015 Gear up for Higher Reliability
® JUNE 2015 THE Path TO Smarter Bearings The True Cost of Bearing Lubrication A Deep Dive Into an Aerospace Gear Manufacturer Automotive Transmissions in Transition www.powertransmission.com Affordable Power Transmission high-quality components at low prices! Synchronous Drives AutomationDirect’s new line of synchronous drive components provide the same positive timing action of gears or chains but with the exibility and quiet running of belts. • Timing pulleys (sprockets) in both aluminum and steel are available in plain bore with setscrew or tapered bushing mounting styles. • Timing (toothed) belt options include several popular Drive Pulleys pitches and widths and are made of fi berglass starting at: reinforced neoprene. $5.25 • Tapered bushings in both QD®and Taper-lock® styles are available in most popular shaft sizes for mounting a variety of pulleys or sprockets to shafts. Get dependable power transmission at low, low prices with SureMotion® synchronous drives! Drive Belts starting at: $2.00 Precision Gearboxes The SureGear® PGCN series is an exceptional gearbox for servo, stepper, and Worm Gearboxes other motion control applications requiring a NEMA size input/output inter- IronHorse® worm gearboxes are manufactured face. Available in NEMA 17, NEMA 23 and NEMA 34 frames sizes with a wide in an ISO9001 certi ed plant by one of the range of ratios, a 20,000 hour service life, and a one year warranty. leading worm gear reducer manufacturers in the world today. They are available in both The SureGear® PGA and PGB series of high-precision servo gear reducers are aluminum and cast iron with a variety of frame excellent choices for applications that require accuracy and reliability at an sizes and ratios. -
Module 3: Power System Overview
1 3|Power System Overview • Generating Station • Transmission System • Transmission Substation • Sub transmission System • Distribution Substation • Distribution System W ESTERN E LECTRICITY C OORDINATING C OUNCIL 2 Course Outline 1. Introduction to WECC 2. Fundamentals of Electricity 3. Power System Overview 4. Principles of Generation 5. Substation Overview 6. Transformers 7. Power Transmission 8. System Protection 9. Principles of System Operation 3 Step -up Transmission Generator Transformer Transmission System Substation Step -down Transformer Distribution Distribution Sub Transmission System Substation System Customer 4 The Power Grid 5 Generating Station W ESTERN E LECTRICITY C OORDINATING C OUNCIL 6 21,000V Generating Station Residential Customer Three-Phase Industrial Customer 7 8 Generating Station Step Up Transformer W ESTERN E LECTRICITY C OORDINATING C OUNCIL 9 RECAP: Putting It All Together 10 230,000V 21,000V 115,000V Transmission Line Generating Station Generator Step-Up Transformer (GSU) 120/240V Residential Customer Three-Phase Industrial Customer 11 12 13 Transmission System W ESTERN E LECTRICITY C OORDINATING C OUNCIL 14 230,000V 21,000V 115,000V Transmission Line Generating Station Generator Step-Up Transformer (GSU) Residential Customer Three-Phase Industrial Customer 15 16 Transmission System What is Transmission? • “Highway” for bulk power • High design voltages • High design reliability 17 Transmission System 18 Transmission System Components • Lines & towers • Power Transformers • Circuit breakers, switches, -
Principles of Shunt Capacitor Bank Application and Protection
Principles of Shunt Capacitor Bank Application and Protection Satish Samineni, Casper Labuschagne, and Jeff Pope Schweitzer Engineering Laboratories, Inc. Presented at the 64th Annual Georgia Tech Protective Relaying Conference Atlanta, Georgia May 5–7, 2010 Previously presented at the 63rd Annual Conference for Protective Relay Engineers, March 2010, and 9th Annual Clemson University Power Systems Conference, March 2010 Originally presented at the 36th Annual Western Protective Relay Conference, October 2009 1 Principles of Shunt Capacitor Bank Application and Protection Satish Samineni, Casper Labuschagne, and Jeff Pope, Schweitzer Engineering Laboratories, Inc. Abstract—Shunt capacitor banks (SCBs) are used in the electrical industry for power factor correction and voltage support. Over the years, the purpose of SCBs has not changed, but as new dielectric materials came to market, the fusing practices for these banks changed from externally fused to internally fused, fuseless, and finally to unfused [1]. This paper gives a brief overview of the four most common types of SCBs. What are the differences between them? Which is the best one to use? What type of protection is best suited for each bank configuration? The paper provides a quick and simple way to calculate the out-of-balance voltages (voltage protection) or current (current protection) resulting from failed capacitor units or elements. While the identification of faulty capacitor units is easy with an externally fused bank, it is more complex with the other types of fusing, making maintenance and fault investigation difficult. This paper presents a novel method to identify the faulted phase and section in capacitor banks. Fig. 1. Four most common capacitor bank configurations I. -
Simplifying Current Sensing (Rev. A)
Simplifying Current Sensing How to design with current sense amplifiers Table of contents Introduction . 3 Chapter 4: Integrating the current-sensing signal chain Chapter 1: Current-sensing overview Integrating the current-sensing signal path . 40 Integrating the current-sense resistor . 42 How integrated-resistor current sensors simplify Integrated, current-sensing PCB designs . 4 analog-to-digital converter . 45 Shunt-based current-sensing solutions for BMS Enabling Precision Current Sensing Designs with applications in HEVs and EVs . 6 Non-Ratiometric Magnetic Current Sensors . 48 Common uses for multichannel current monitoring . 9 Power and energy monitoring with digital Chapter 5: Wide VIN and isolated current sensors . 11 current measurement 12-V Battery Monitoring in an Automotive Module . 14 Simplifying voltage and current measurements in Interfacing a differential-output (isolated) amplifier battery test equipment . 17 to a single-ended-input ADC . 50 Extending beyond the maximum common-mode range of discrete current-sense amplifiers . 52 Chapter 2: Out-of-range current measurements Low-Drift, Precision, In-Line Isolated Magnetic Motor Current Measurements . 55 Measuring current to detect out-of-range conditions . 20 Monitoring current for multiple out-of-range Authors: conditions . 22 Scott Hill, Dennis Hudgins, Arjun Prakash, Greg Hupp, High-side motor current monitoring for overcurrent protection . 25 Scott Vestal, Alex Smith, Leaphar Castro, Kevin Zhang, Maka Luo, Raphael Puzio, Kurt Eckles, Guang Zhou, Chapter 3: Current sensing in Stephen Loveless, Peter Iliya switching systems Low-drift, precision, in-line motor current measurements with enhanced PWM rejection . 28 High-side drive, high-side solenoid monitor with PWM rejection . 30 Current-mode control in switching power supplies . -
Flexible Distribution Systems Through the Application of Multi Back-To-Back Converters : Concept, Implementation and Experimental Verification
Flexible distribution systems through the application of multi back-to-back converters : concept, implementation and experimental verification Citation for published version (APA): Graaff, de, R. A. A. (2010). Flexible distribution systems through the application of multi back-to-back converters : concept, implementation and experimental verification. Technische Universiteit Eindhoven. https://doi.org/10.6100/IR673052 DOI: 10.6100/IR673052 Document status and date: Published: 01/01/2010 Document Version: Publisher’s PDF, also known as Version of Record (includes final page, issue and volume numbers) Please check the document version of this publication: • A submitted manuscript is the version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. -
Aspects on Dynamic Power Flow Controllers and Related Devices for Increased Flexibility in Electric Power Systems
Aspects on Dynamic Power Flow Controllers and Related Devices for Increased Flexibility in Electric Power Systems Nicklas Johansson Royal Institute of Technology School of Electrical Engineering Division of Electrical Machines and Power Electronics Stockholm 2011 Submitted to the School of Electrical Engineering in partial fulfillment of therequirementsforthedegreeofDoctorofPhilosophy. Stockholm 2011 ISBN 978-91-7501-058-8 ISSN 1653-5146 TRITA-EE 2011:050 A This document was prepared using LTEX. Abstract This thesis studies different aspects of Flexible AC Transmission System (FACTS) devices which are used to improve the power transfer capability and increase the controllability in electric power systems. In the thesis, different aspects on the usage and control of Dynamic Power Flow Controllers (DPFC) and related FACTS devices are studied. The DPFC is a combination of a Phase Shifting Transformer (PST) and a Thyristor Switched Series Capacitor (TSSC)/Thyristor Switched Series Reactor (TSSR). The thesis proposes and studies a new method, the Ideal Phase-Shifter (IPS) method, for selection and rating of Power Flow Controllers (PFC) in a power grid. The IPS method, which is based on steady-state calculations, is proposed as a first step in the design process for a PFC. The method uses the Power controller plane, introduced by Brochu et al in 1999. The IPS method extends the usage of decoupling methods in the Power controller plane to a power system of arbitrary size. The IPS method was in the thesis used to compare the ratings of different PFC:s required to improve the power transfer capability in two test systems. The studied devices were here the PST, the TSSC/TSSR and the DPFC. -
Single-Wire Electric-Field Coupling Power Transmission Using Nonlinear Parity-Time-Symmetric Model with Coupled-Mode Theory
energies Article Single-Wire Electric-Field Coupling Power Transmission Using Nonlinear Parity-Time-Symmetric Model with Coupled-Mode Theory Xujian Shu and Bo Zhang * School of Electric Power Engineering, South China University of Technology, Guangzhou 510641, China; [email protected] * Correspondence: [email protected]; Tel.: +1-360-006-6030 Received: 20 January 2018; Accepted: 26 February 2018; Published: 1 March 2018 Abstract: The output power and transmission efficiency of the traditional single-wire electric-field coupling power transmission (ECPT) system will drop sharply with the increase of the distance between transmitter and receiver, thus, in order to solve the above problem, in this paper, a new nonlinear parity-time (PT)-symmetric model for single-wire ECPT system based on coupled-mode theory (CMT) is proposed. The proposed model for single-wire ECPT system not only achieves constant output power but also obtains a high constant transmission efficiency against variable distance, and the steady-state characteristics of the single-wire ECPT system are analyzed. Based on the theoretical analysis and circuit simulation, it shows that the transmission efficiency with constant output power remains 60% over a transmission distance of approximately 34 m without the need for any tuning. Furthermore, the application of a nonlinear PT-symmetric circuit based on CMT enables robust electric power transfer to moving devices or vehicles. Keywords: single-wire; electric-field coupling; parity-time-symmetric; coupled-mode theory 1. Introduction Since the discovery of electricity, the power transmission has mainly depended on the wires, and the way of power transmission through wires requires at least two wires to provide conduction paths for conduction current, which may be difficult to install but also has a large number of safety issues, such as the risk of fire and electric shock caused by short circuits. -
Engineering Mini Holiday Lights Series and Parallel Circuits
1 Engineering Mini Holiday Lights Jeffrey La Favre The small light bulbs we are using for our activities were cut from strings of mini holiday lights. The strings contained 100 light bulbs arranged in two sets of series circuits (50 lights in each series circuit). This paper will explore the reasons why the bulbs were designed to operate in series circuits. If your parents own strings of incandescent mini holiday lights, they might tell you they have had trouble with them after a few years of use. If a light bulb burns out or is no longer tight in its socket, all of the lights in the circuit may not glow when plugged in. It can be frustrating to find the bad bulb and replace it to repair the light string. You might ask why the lights were designed to operate in a series circuit due to this problem. In this paper I will try to explain why the lights were designed in series circuits. The explanation will include some math that might be difficult to understand. But if you look carefully at the math, you will discover that it is really nothing more than adding, subtracting, multiplying and dividing. Series and Parallel circuits After you have completed lesson one on series and parallel circuits, you should have some understanding of the way electricity behaves in these circuits. Let us review the two circuit types and cover some important points that will help you understand the rest of this paper. In a series circuit the current flows through one bulb, then the next and then the next.